Generality
Varenicline is a drug with specific indications to help patients stop smoking. Varenicline represents an alternative to the use of other drugs used to combat smoking addiction, such as bupropion and nicotinic replacement therapy.
Varenicline - Chemical Structure
Some studies have even shown that varenicline may be more effective than bupropion in smoking cessation therapy and relapse prevention.
Varenicline has been approved for entry into the European Union in 2006.
Action mechanism
Varenicline is a partial agonist of nicotinic receptors. More in detail, varenicline interacts with the α4β2 nicotinic receptor present in the brain which is the same receptor to which the nicotine resulting from tobacco smoke binds.
By binding to this receptor, varenicline is able to partially stimulate it and this causes the symptoms induced by abstinence from smoking to decrease. Furthermore, varenicline prevents the nicotine from binding to the aforementioned receptor, so that - in which case the patient resumes smoking during drug therapy - there is a decrease in the pleasure and satisfaction associated with smoking.
Side effects
Smoking cessation can cause some side effects even if you are undergoing drug therapy. Such effects usually consist of mood alterations, insomnia, concentration difficulties, increased appetite, increased body weight and decreased heart rate.
Furthermore, varenicline itself can also cause side effects, although not all patients experience them.
Among the most common adverse effects that may occur during varenicline therapy, we recall:
- Headache;
- Nose and throat inflammation;
- Sleep disorders;
- Altered dreams;
- Increase or decrease in appetite;
- Increased body weight;
- Drowsiness;
- dizziness;
- Shortness of breath or cough;
- Chest infections;
- sinusitis;
- Burning in the stomach and abdominal pain;
- He retched;
- Diarrhea or constipation;
- Difficulty of digestion;
- Skin eruptions;
- Joint and muscle pains.
dosage
Varenicline is available for oral administration as tablets.
Generally, a dose of 0.5 mg of varenicline per day is administered for the first three days of therapy. Then, from the fourth to the seventh day of therapy, the dose of drug used is 0.5 mg to be taken twice a day. Finally, from the second week of therapy until the end of treatment, the dose of varenicline is increased to 1 mg, to be taken twice a day.
Treatment usually lasts twelve weeks and smoking should be stopped within the fifth week of starting therapy.
After 12 weeks of therapy - if deemed necessary - the doctor may decide to prescribe a further twelve-week treatment to prevent the onset of possible relapses.
During therapy with varenicline it is very important to follow the instructions given by the doctor scrupulously, both as regards the amount of drug to be taken and the frequency of administration and the duration of the treatment.
Finally, it should be emphasized that in patients strongly motivated to quit smoking there is a greater chance of successful drug therapy.
Use during pregnancy and lactation
Varenicline should not be used in pregnant women. Furthermore, although no studies have been conducted to this effect, varenicline may be excreted in breast milk. Therefore, breastfeeding mothers should seek medical advice before starting any therapy with this medicine.
In any case, pregnant women and breastfeeding mothers should always seek medical advice before taking any type of medication.
Contraindications
The use of varenicline is contraindicated in patients with known hypersensitivity to varenicline itself. Furthermore, the use of varenicline is not recommended in children and adolescents under 18 years of age.
